This seems to be just a support thread with two comments? Was kinda expecting a full bug explanation or something with a bit more substance as to why this is happening beyond 'it's just very odd'.
You're asking a bit much from an HP support forum - this is the same level as the Microsoft support forums, aka the blind leading the blind.
Frankly I'm amazed that the reply, despite smelling of useless first-line tech support by wasting an entire paragraph to repeat his question pretty much verbatim, managed to actually offer a useful suggestion of testing with an external keyboard.